Inherited or familial pituitary tumor syndromes such as multiple endocrine neoplasia type 1 and Carney complex provide an important insight into the genetics and molecular pathology of endocrine cancers. Our understanding of these conditions is expanding rapidly due to the identification of the genes and proteins affected and the availability of murine knockout models. The successes achieved to date in understanding multiple endocrine neoplasia type 1 and Carney complex have helped in the identification and study of new inherited pituitary tumor syndromes such as isolated familial somatotropinomas. This review assesses the current status of research into the clinical features, genetics and molecular pathologies of multiple endocrine neoplasia type 1, Carney complex, and isolated familial somatotropinomas, and details ongoing work to delineate familial isolated pituitary adenomas, a potentially new clinical entity.